By Joel L. Swerdlow, National Geographic Senior Writer
Aristotle believed that the center for thought lies in the heart and that the brain helps cool the body. Drowsy people hang their heads, he said, because brain-created heaviness forces the head downward. We laugh now, but many experts agreed with Aristotle as recently as the late 19th century. Indeed, we still know relatively little about the three pounds of flesh that makes us human.
This is not surprising given that the human brain, with its many billions of cells, is the most complex object in the known universe. But we have learned more in the past ten years than in all previous history, thanks to technologies that allow researchers to see inside living brains and examine brain functions at the subcellular level.
That we have entered an era of extraordinary discovery becomes clear moments after I ring the doorbell of eight-year-old Matthew Simpson's home in Albuquerque, New Mexico. The scene is a Hollywood version of how childhood is supposed to be: Bikes on the driveway, a green lawn, and next-door neighbors playing basketball.
Matt stands beside his mother as we chat on the porch. He can see that I am feeling the New Mexico heat. "Would you like a glass of water?" he asks. It is the last day of second grade, and Matt is proud of his report card. It shows respectable grades, good behavior, and steady improvement. Two years ago surgeons removed nearly half of Matt's brain.
Matt's first three years were textbook normal. Just before his fourth birthday, he began to experience seizures--electrical misfirings that impede brain functions. Medicines did nothing as seizures threatened to turn fatal. The eventual diagnosis: Rasmussen's encephalitis, a rare and incurable condition of unknown origin.
Desperation brought his parents, Jim and Valerie Simpson, to Ben Carson, a pediatric neurosurgeon at Johns Hopkins Hospital in Baltimore, Maryland. Carson recommended a hemispherectomy, removing the left hemisphere of Matt's brain. Matt would lose half his cortex, tightly packed folds that handle thought processes and most of what makes us human. The empty area of the skull, Carson explained, would fill with cerebrospinal fluid at about a teaspoon every five minutes and would remain filled.
The operation could lead to crippling, coma, death, or recovery. Carson would not guess at odds. Nor would he say how much of Matt would remain with half his cortex gone.
Although hemispherectomies were performed in the 1940s, few patients lived. Pediatric neurosurgeons revitalized the procedure in the mid-1980s, because of advances in brain scans and in ability to combat bleeding.
Several dozen hemispherectomies are performed each year now in the United States, usually as treatment for Rasmussen's encephalitis and forms of epilepsy that destroy the cortex but do not cross the groove separating left and right hemispheres. Patients can live because neither the disease nor the operation touches areas that control basic functions: the cerebellum, which coordinates movement; the diencephalon, which facilitates emotions and regulates body functions; and the brain stem, which maintains breathing, heart rate, and other life-support systems.
As Matt began to suffer worsening seizures, sometimes every three minutes, the Simpsons had no choice.
Matt's parents and half sisters, 16-year-old Stacy and 13-year-old Jamie, show me a scan of Matt's brain. I see the outline of a skull. One side has shapes in white, gray, and black. The other is all black, entirely filled with fluid.
The operation left a scar that runs along one ear and disappears under his hair. But his face has no lopsidedness. The only visible effects of the operation are a slight limp and limited use of his right arm and hand. He also has no right peripheral vision in either eye.
Matt and his mother drive out on errands. "I see a sailing ship and a huge elephant," he says, looking at shapes in clouds. She discusses details with him and asks if he sees anything else. Matt describes a clown and a frog.
I appreciate such brain-stimulating games when I join his weekly session of speech and language therapy. One typical activity is word games. Therapist Joan Harden places cards in front of him. Matt turns one over. It says "fast things." He must now name as many fast things as he can in 20 seconds. "Car...truck...train...plane," he says. The next card says "soft things." Matt says "Butter...the middle of bread" and stops. A child his age should name from six to eight things each time. Matt names only four and two. Is this because he has half a brain or because he suffered seizures between ages 3-1/2 and 6-1/2? No one knows.
In the past two months Matt has made nine months' progress in language use. "In the improvement he has made it appears he is fostering and accelerating the growth of dendrites, threadlike extensions that grow out of neurons, the specialized cells of the nervous system," Harden explains. "The neurons seem to be making better connections."
More connections among the brain's estimated hundred billion neurons mean a better functioning brain. Connections come from inherited growth patterns and in response to stimuli, including internal stimuli like imagined sensations. The body receives information at the "periphery"--the neuroscientists' chauvinistic word for everything that is not the brain--and encodes it as nerve impulses. When these electrical impulses reach the brain, they trigger the release of messenger chemicals such as glutamate, which in turn induce electrical impulses as they travel from one neuron to another. This electrochemical process, the basis of brain communication, sometimes stimulates growth of new dendrites. Thus rats raised in cages full of toys have more brain mass--probably from more dendrites--than do rats in empty cages.
The brains of infants suffering from some forms of mental retardation have fewer dendrites than do the brains of healthy babies. Brain-imaging studies conducted by Harry T. Chugani, a pediatric neurologist at Children's Hospital in Detroit, Michigan, suggest that dendrite production rises rapidly after birth and remains at a peak level from about age four to age ten. In fact, during these years a child's brain has many more connections than does an adult's and uses twice as much energy.
Until recently, experts believed that genes program most dendrite growth. People like Matt demonstrate that the brain has unexpected flexibility--what scientists call plasticity. This plasticity promises to redefine basic concepts. The left side of the brain of a right-handed person--precisely what was cut out of Matt--specializes in handling music, poetry, and mathematics. Yet Matt enjoys piano lessons, and math is his strongest subject in school. Somehow, knowledge and capability traveled from one side of his brain to the other.
Such transfers seem to defy biology. Does an undiscovered conduit exist, or does each side have dormant capacity to assume functions of the other? The ability to transfer is highest before adolescence, during the years of peak dendrite growth. But transfer, albeit limited and slow, also occurs when strokes kill portions of an adult brain.
Other evidence of transfer comes after amputations. Every part of the body is connected to the cortex. Touching something with your left hand, for example, activates a particular part of your right cortex, and touching something with your right hand stimulates a mirror-image portion of your left cortex. Next to these sections of the cortex, for reasons no one understands, are areas connected to the nostrils (artwork, pages 14-17). After his hand was amputated, one man reported tingling in his missing pinky when researchers dripped warm water under his nostrils. The part of his cortex connected to his nostrils had seized areas of the cortex that had received signals from the now missing fingers. Likewise, brain scans of Braille readers show that their reading fingers stimulate more cortical area than do fingers of sighted people. Presumably, extra use of these fingers prompts expansion into neighboring cortical territory.
The Simpson family says that Matt's personality never changed through seizures and surgery--an observation made by most families whose children have had hemispherectomies. "He started as a nice, caring child and he stayed a nice, caring child," Valerie says. For me, the best moment comes one evening while Matt is drawing with crayons and the adults are talking. Matt interrupts us. Jim asks him to stop. Interruptions continue. Jim warns Matt he will be punished. Matt persists. "Why are you smiling?" Jim asks me.
"Because he acts like a normal eight-year-old," I reply.
"He is a normal eight-year-old," says Jim.
Many people learned in school that we use only 10 percent of our brains, a belief that may have been based on psychologist William James's assertion in 1910 that we use "only a small part" of our mental powers. People like Matt certainly indicate that much of the brain is redundant. I can imagine Matt telling his dates ten years from now, "You won't believe this, but I have half a brain."
Matt's resiliency is dramatic, yet no more so than a common occurrence: the development of new human brains. I look into a microscope at an eight-cell human pre-embryo, the product of laboratory, or in vitro, fertilization. The egg and sperm were taken from a husband and wife whose family history includes a fatal genetic disease. If scientists at the Illinois Masonic Medical Center in Chicago determine that this gene is not present, they will implant the pre-embryo into the mother.
The pre-embryo resembles a transparent bubble floating in space. Although I feel like a voyeur, I cannot stop looking through the microscope. Each cell is rounded, the cell walls are thick lines, and dark smudges are cell nuclei--exactly what I expect. But why does each of the eight cells look exactly the same? Some will grow into the brain, others into the heart and skin. Maybe the microscope is not strong enough to reveal differences.
"They are the same," geneticist Yury Verlinsky explains. "From each of these cells, every cell in the body will grow. The differentiation begins once the cells have divided into about a hundred, about three days after the egg is fertilized. No one knows how it happens. There is no `master builder' cell."
During early pregnancy, neurons can grow at a rate of 250,000 a minute. Perhaps half die before a baby is born. This "pruning down" may eliminate flawed neural connections. Gerald Edelman, a neurobiologist at the Neuroscience Institute in La Jolla, California, sees a tropical rain forest in which "neural Darwinism" selects the fittest neurons.
Whatever triggers brain development, it is the most sensitive part of fetal growth. Vitamin deficiency, maternal smoking, or prenatal exposure to alcohol, chemicals, or too much heat may prevent neural development or cause damage to neurons.
Women who have influenza while pregnant, some studies suggest, are more likely to have children who develop schizophrenia, as are women who suffer severe malnutrition during pregnancy. Other evidence, like family histories, indicates that inherited genetic malfunctions contribute to schizophrenia.
Advancing knowledge about the role of the brain's physical structure in mental illness should change our perceptions about such diseases. Including depression and manic depression, mental illnesses afflict more than 20 percent of all Americans.
"That's the frontal cortex of Steven Elmore, a 33-year-old schizophrenic," says Dan Weinberger, a neurologist and psychiatrist at the National Institute of Mental Health, as he flips an image onto his computer. We are in the den of his home in Washington, D.C. Weinberger flips an image from Steve's identical twin, David--who is not schizophrenic--next to the first image. "Brains normally differ more from one another than do fingerprints," Weinberger says. "But these brains are genetically identical and should look the same. They don't."
The differences between Steve's and his brother's are clear. Steve's has less cortex and larger fluid-bearing ventricles. "The part of the cortex he's missing," Weinberger says, "serves as perhaps the most evolved part of the human brain. It performs complicated tasks such as thinking organized thoughts. This might help explain why paranoid delusions and hallucinations are characteristic of schizophrenia."
Weinberger clicks further into both brains. The images also show that Steve's has a smaller hippocampus. The hippocampus, from Greek for "seahorse" because of its shape, facilitates memory storage. Such an abnormality may be why some schizophrenics have memory problems.
"The loss of brain tissue does not worsen with time, and it does not improve with medication," Weinberger says. "It may be there from birth, and it may be partly the product of genes that make a person vulnerable. It's hard to know what's really going on since schizophrenia doesn't usually manifest until late adolescence."
Writing in the fourth century B.C., Hippocrates said that "madness" comes from too much "moistness" in the brain--exactly what Weinberger has just shown me. For Hippocrates, this was a lucky guess based on the belief that four "humors"--earth, fire, air, and water--control health.
As is common when a scientific venture is in its infancy, discoveries raise more questions than they answer.
"How do genetic characteristics interact with environmental influences?" Weinberger asks me. "Why doesn't schizophrenia appear sooner? Can we devise a way to treat patients before symptoms appear?"
Western medicine used to blame schizophrenia on upbringing or the patients' self-indulgence. "Now at least we know it has physical aspects," Weinberger says. "The same is true of manic depression and many other so-called mental illnesses."
Such insights have led to drugs that affect brain chemistry. Key to many of these drugs is dopamine, a naturally occurring chemical in the body that responds to external and internal stimuli by saying to neurons, "Attention must be paid." Neurons have at least eight different types of receptors for dopamine; each absorbs a different message. Restricting the actions of dopamine reduces schizophrenic symptoms.
This physical aspect of schizophrenia should prompt changes in our attitudes--many people still see mental illness as a stigma--and in insurance policies that grant less coverage for mental illness.
Whatever the cause, about one in every hundred Americans--including as many as one-third of homeless adults--have schizophrenia. At a busy corner I see telltale traits: Some homeless people stand alone and look particularly disheveled, strange even among the strange. One woman wears a wire-and-foil hat. "To keep my skull from opening," she says.
What went wrong for these people? Lack of money and bad luck are likely suspects. About 40 percent of Americans with severe mental illness receive no treatment. "I'd be on the street myself if it weren't for my family, doctors who care, and medicine," Steve Elmore tells me a few days later when I visit his Indianapolis, Indiana, apartment. He owns his own car, handles his own finances, and works for a mental-health agency that understands a schizophrenic's need to avoid stress.
Steve's apartment has few books, mostly biographies of the Beatles, because Steve can concentrate only long enough to read in short spurts. Shelves of rock-and-roll discs line every wall. "When an episode starts, I lie down and listen to rock," Steve says. "I feel like a nothing, like I'm falling apart, like I'm not on this planet. My brain gets stuffy, like people are trying to stuff cotton balls in it. I can feel the brain pressing against the skull. If I went off my meds, I'd be weird in about a week."
Steve asks if I have ever had to work hard at something. "That's how it is," he says. "The medicines don't do all the work. It's a struggle." That evening we stay up late. Steve describes how his life changed at 19: anger at noises only he heard, walks through the neighborhood screaming. During childhood, he said, he was a little wilder than his twin but not significantly different. I tell him about a recent study showing that home movies of children who later became schizophrenic reveal jerky body movements when compared with siblings. "Maybe," Steve says with a smile, "but I was always a better basketball player than my brother."
Steve still hears voices. "Have they been talking now?" I ask.
"Sure," he says. "I told them you manage my rock band." I take out an empty pad and ask him to write what he hears as our conversation proceeds. Soon, "Jerk," "Shut up!" "You're a creep," "Get out of here," and similar statements fill the page.
"Do you realize that no one is saying those things?" I ask.
He shakes his head, exasperated. "Maybe not," he says, "but I know the voices are likely real."
Later that night he takes out a plastic pillbox and swallows extra Stelazine, a drug that blocks binding of dopamine to receptors and helps silence the voices. Treatment of his schizophrenia as a physical illness fits in with a larger pattern: Scientists increasingly argue that everything we experience can be reduced to a physical component. These "reductionists" are the ultimate cartographers: Everything, they say, exists at a particular point on the brain map.
Some reductionists stake out an extreme position. Francis Crick, who along with two colleagues won the 1962 Nobel Prize in medicine for deciphering the DNA code that defines genes, says that "You, your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells."
The uniquely human "consciousness"--variously defined as language, introspection, self-awareness, and abstract thinking--eludes scientific measurement. Albert Einstein conceived of the theory of general relativity after imagining a person taking a ride in a box through space. Yet postmortem study of Einstein's brain has indicated nothing that explains how he used such visualizations to devise abstract theories.
And who will map the mixture of myth, morality, faith, pain, and joy that make up our spiritual geography? "We will never find a satisfactory mechanistic explanation" for such phenomena, said Lewis Thomas, the late physician and biologist who wrote best-sellers such as The Lives of a Cell. Is this because measurements are too crude or because scientists are trying to measure the immeasurable?
Examining animals suggests a relationship between brain size and intelligence. Human brain size leveled off about 100,000 years ago, perhaps limited by what can fit through the female pelvis--the brain is approximately one-quarter its final size at birth; the rest of the body is one-twentieth. But among humans, no size-intelligence relationship exists.
"Bigger is not necessarily better," Stephen Kosslyn, a Harvard University psychologist who studies how the mind creates mental images, explains to me. "Bigger could be worse because it impedes rapid communication between neurons within the brain."
But the size of a certain brain part might be crucial. How did Michelangelo see, Shakespeare feel, and Mozart hear? One study reveals that the planum temporale in the left hemisphere, a part of the brain associated with auditory processing, is larger in musicians than in nonmusicians, and is larger still in musicians with perfect pitch.
Howard Gardner's influential Frames of Mind: The Theory of Multiple Intelligences argues that every individual has one or more of seven distinct intelligences--such as spatial, linguistic, and musical. Does each "intelligence" have its own physical manifestation? Gardner resists putting too much faith in physical findings. "Intelligence is a capacity," he says. "To ask `Where in the brain is intelligence?' is like asking, `Where is the voice in the radio?'"
Vincent van Gogh may have suffered from temporal lobe epilepsy, which triggered electrical hyperactivity of the brain. Did it affect works, such as "Starry Night," noteworthy for their hallucinatory imagery? "Remember not to carry such assertions too far," says Harry Rand, an art historian and a senior curator at the Smithsonian Institution. "Every artistic genius does not have a brain anomaly, and everyone with a brain anomaly is not a great artist. Art is far more than something that automatically results from a physical characteristic."
Still, the mapmakers' growing success demands attention. One gene produces an enzyme, monoamine oxidase A, that helps brain cells communicate. Some men inherit an abnormal gene that fails to produce enough monoamine oxidase A. Other neurotransmitters accumulate, and the person--for unknown reasons--becomes violent when faced with stress. If a young boy is known to carry this gene defect, should he receive special treatment? Should family or society impose restrictions upon him? As brain discoveries mount, who will make such decisions?
Aldous Huxley, author of Brave New World, noted humankind's emergent manipulation of its basic biology in the 1950s and warned in 1961, "For heaven's sake be careful." The need for care is particularly acute as researchers discover the physical basis for what may define us most as humans, our emotions.
Candace Pert, a former National Institutes of Health pharmacologist who now heads her own research firm, has pioneered much of this work. To explain it, she takes me back to high school biology. "We were all taught that synapses, the distance between two neurons, are crucial," Pert says. "We now realize there's a communications network that operates via receptors and their `informational substances.' Communications between cells occur via chemical reactions and transfer of electrochemical energy.
"When trying to find why morphine affects the brain," she continues, "we found that the brain also relies on neuropeptides, strings of amino acids that float throughout the body and convey information by attaching themselves wherever they find a welcoming receptor. These are extraordinary, because they trigger emotions. During the 1950s, experiments revealed that electrical stimulation of certain areas of the cortex provoked emotions--exactly the areas that are filled with neuropeptides. At least 60 neuropeptides have been discovered so far."
She pauses and repeats one sentence because she knows it must sink in slowly. "Emotions," she says, "are neuropeptides attaching to receptors and stimulating an electrical change on neurons."
We traditionally perceive the brain in terms of prevailing technology. It has been a mechanical water clock, hydraulic pump, telephone switchboard, and liquid-cooled parallel supercomputer. For Pert to describe a communications network therefore makes sense. But I resist. "Joy? Grief? Love? All biochemical?" I ask. She nods, yes.
"All love, for everyone, involves the same peptides?" I ask. Again, she says, "Yes."
Pert's husband, immunologist-virologist Michael Ruff, joins us for lunch. They began to date while working together at the National Institutes of Health. "Are neuropeptides popping right now because you're next to each other?" I ask.
"Of course," Pert says, putting one arm around Ruff. He looks away, trying to hide his smile. "When I fell in love with my wife, I gave her my heart, not my neuropeptides," I tell Pert.
"Neuropeptides are in your heart too," she says. "Experiments show that the spleen, thymus, bone marrow, lymph glands, and dorsal horn of the spine also produce neuropeptides." Neuropeptides, she says, even come from the stomach, giving new validity to the expression "gut feeling."
The mind is not only in the brain, Pert argues. It is also in the flow of neurocommunicators throughout the brain, glands, and immune system.
Some of Pert's theories may be incomplete, but they illustrate--as do the experiences of every researcher and patient I have met--that we must look at ourselves in new ways and accept new truths.
The blood-brain barrier is a typical example. These tightly packed capillaries, located throughout the brain, restrict access, because the brain is sensitive to small fluctuations in bloodborne material. Communications between brain and immune system, however, imply a steady flow of peptides and more openness than experts have believed thus far. Once we accept this possibility, we may better understand the dramatic increase of brain cancer in industrialized countries. Whether the brain is unusually susceptible to carcinogens remains unclear, but carcinogens do seem to cross the blood-brain barrier.
Some new truths are not as new as they seem. The flow of substances between our brain and body seems like a radical idea, but for 4,000 years Chinese medicine has said that control over the brain rests with the liver, heart, spleen, lungs, and kidneys. These organs communicate, according to Chinese medicine, via energy channels that form the basis for treatments such as acupuncture.
Likewise, modern science has just started to examine links between the brain and immune system. Eastern philosophy and the Old Testament, however, have always linked mental processes and health. "A merry heart doeth good like a medicine," says the Book of Proverbs, "but a broken spirit drieth the bones."
Thus, Pert and colleagues are on old terrain when they demonstrate that immune and brain cells constantly chatter via neuropeptides. Peptides from the brain cause immune cells to proliferate, and some immune cells release peptides that affect brain function. Macrophages, the immune cells that usually reach an invader first, are, in effect, mobile synapses, carrying and releasing neuropeptides throughout the body.
Implications are obvious. Stress, for example, increases susceptibility to disease by compromising the immune system. Thus, participation in support groups--which presumably reduces stress--may increase the longevity of cancer patients and the production of cancer-fighting cells.
A group of men and women with a variety of life-threatening cancers meets weekly in the Cancer Resource and Support Center in Pasadena, between Baltimore and Annapolis, Maryland. Their chairs are circled as they discuss symptoms, pain, and fear. Even such depressing topics evoke laughter. Al Smith, 64, whose colon cancer has spread throughout his body, gets loud roars when he describes the doctor who said he had six months to live. "That was five years ago," Al says. "My goal is to go to him in five more years and say, `Liar, liar, pants on fire.'" Donna Seafolk-Kopp, 43, who has ovarian cancer, grabs everyone's attention with "It keeps getting bigger," and then reveals that she means a party celebrating her upcoming master's degree.
As the meeting adjourns, I notice Hugh McLeod's T-shirt: two fingers about to touch--a reproduction of God giving life to Adam in Michelangelo's ceiling in the Sistine Chapel. Hugh has thick arms, wide shoulders, a healthy aura. His story: "I'm a 41-year-old retired Air Force officer now working as a consulting engineer. For six years doctors treated me for a fungus infection under my right big toe. When the toe finally split open, they diagnosed `level III melanoma with a large satellite node.' Four months ago they cut off the toe. They said that blood or lymph could carry the cancer anywhere, and that it is very aggressive and could appear in my brain. The doctors say scans will definitely find the new cancers, and they have no treatments to offer."
I ask what percentages the doctors gave him. Hugh strokes his beard. Silence. "Why haven't you given in to despair or terror?" I ask. He smiles. "I believe that I am fine and will stay fine," he says. Hugh then describes two weeks at Getting Well, a behavioral medicine program in Orlando, Florida, designed to help people with the emotional and spiritual aspects of serious illnesses. "I had believed that to have emotions is a sign of weakness and illness," he says. "I have experienced an awakening that could not have happened without the illness. Whatever I deal with, relationships with my children from my first marriage, the fact that career opportunities have taken me to another city, problems with my current boss, I strive to be honest with myself and others about my feelings. This honesty helps my body protect itself. I have also learned to use mental imaging to produce anticancer chemicals such as killer T cells and interferon. I image two or three times a day."
Several years ago a friend of mine underwent coronary artery surgery. Every night he visualizes brushes scrubbing his artery walls. He then follows the yellow plaque through his kidney until it is flushed from his body. "I don't talk much about this," he once told me. "People aren't ready to understand." My friend emphasizes, as Hugh does, that he images in addition to standard medical care.
Hugh's living room has a dog-eared copy of Walt Whitman's Leaves of Grass. "He had a zest for life," Hugh says, opening the book to
The thin red jellies within you or within me, the bones and the marrow in the bones,
The exquisite realization of health;
O I say these are not the parts and poems of the body only, but of the soul,
O I say now these are the soul!
Hugh darkens the room, lights two candles, and sits on the sofa. When he takes off his shoes, I see that the end of one sock is empty.
"You use what works best," he explains. "Some people say they `breathe in color.' I have created a neon bug whacker that goes into my brain." He puts his feet on the coffee table, punches on a tape recorder and closes his eyes. I sit on the other end of the sofa and close my eyes too.
Music on the tape plays in the background as a soft voice says, "Imagine an opening on top of your head. The light of stars, suns, galaxies, heavens, of love enters your body." I soon float out with the words.
Is Hugh tapping into some primal ability when the tape tells him to "take a moment to explore all the routes and highways of your brain and mind. You'll find one that has to do with your immune system, and circulation, and so on. Turn the right valves. Turn off those that carry nourishment to the disease." Or is he calming himself with a harmless exercise? All we know for sure is that he is entering terra incognita.
As I leave, I notice some pills. "What are those?" Hugh hesitates. "Muscle relaxers for my shoulder," he says. "It's been getting stiffer. I can't move my neck well. It's been going on for about two weeks. I have a scan scheduled for next week." He sees the look on my face and adds, "I sure hope it's nothing bad." I call Hugh six months later. He tells me that the shoulder pain was a pulled muscle. "Everything's going well with me," he says, "but the group lost a couple of people."
Once, when driving with Hugh, I asked why he so diligently puts on his seat belt. If death creeps within, why worry about an accident? He said he is working hard to live and does not want to crash his head through the windshield.
Hugh is right. Despite increased use of seat belts and helmets, brain injury disables or kills someone in the United States every two and a half minutes. Although the brain is the only organ covered mostly by bone, it floats in a thin cushion of fluid and can bounce against the skull. Even shaking a baby can cause permanent brain damage.
On October 13, 1986, Patsy Cannon was driving her nine-year-old daughter to school when another woman's car collided with them. Only Patsy was hurt. Her seat belt came loose and her head hit the windshield and then the side window.
Patsy awoke several hours after the accident. She felt fine but had severe amnesia. Her amnesia is "retrograde": She has no difficulty remembering events after the accident but can remember nothing from before. The only visible evidence of injury is a slight indentation along the top of her forehead.
A photograph taken a week before the accident shows Patsy between two other young women. All are laughing. "I apparently was a workaholic in corporate America," Patsy says. "That person is dead; I am a new person." Ironically, Matt Simpson lost half his brain and kept his personality. Patsy has all her brain and lost her entire self.
Patsy stayed in Birmingham, Alabama, her hometown, and reinvented herself as an advocate for people with brain injuries. United Cerebral Palsy of Greater Birmingham has hired her to design and direct supported living and employment programs that allow adults with brain injuries to regain control of their lives outside institutions. She invites me to join a group for young adults.
"We took a lickin' and keep on tickin'," one tells me. As they discuss failures and triumphs, I witness the hardest type of courage--not the flash of bravery but the daily resolve not to quit. For my slow-speaking companions, courage is willingness to speak, write a poem, get an apartment, hold your hand to make twitching stop, ride a bicycle, ask a question, laugh, and, most important, let yourself be who you are.
Patsy and I visit the Spain Rehabilitation Center, a not-for-profit facility of the University of Alabama Hospital System. An automobile accident survivor who recently emerged from a two-month coma wears a hospital gown and a baseball cap. Neurons can resprout dendrites throughout life, so hard work and encouragement could restore much of his brain function. But he slumps in a wheelchair, his eyes unmoving. Drops of spittle edge down his chin. "He doesn't respond much," a nurse says. Patsy kneels. Her lips unleash a stream of chatter, part purring and part pep talk. His mouth moves, but nothing comes out. By shaking his head, he communicates a strong preference for the Auburn University football team over the University of Alabama. He accepts her offer of an alphabet board so he can point to letters, and spells the names of his two children. Patsy does not tell him that the automobile accident killed one of them.
Shortly after one of my visits with Patsy, my nine-year-old son, Aaron, comes home with a bad headache. He had banged his forehead and apparently lost consciousness. He has no outward injuries, but six hours later his headache and dizziness are still getting worse. At the emergency room his name goes on the chalkboard followed by "head injury." When the doctor says "a concussion, no brain damage," I hug Aaron--and realize why people I have met on this story hug so often. They know too well how fragile we all are.
For Patsy, fragility means the need to relearn everything. "I learned to speak through tapes and friends," she says without emotion. "Once a friend told me it was `raining cats and dogs,' and I panicked. I ran to the window expecting to see flying animals." Four months after the accident she was hospitalized again with bleeding ulcers. "No amount of learning," she tells me, "could silence the internal screams."
Relearning love came hardest. "When I saw my nine-year-old daughter, Leah, I felt nothing," Patsy says. "It could have been any child off the street." She squints as though trying to see through some fog that separates us, and asks, "How do you explain love to someone who has no memory of love?"
Leah describes her mother's return from the hospital. Patsy and Leah's father were divorced before the accident, and no other adult was around. "Can you cook?" Leah asked. Patsy said "show me" and almost burned the house down. Leah easily convinced her mother that children never do homework and all mothers take their daughters shopping every day after school. "At the mall my mother bought herself dresses with floral patterns," Leah tells me. "It scared me, because I realized she was a different person. The mother I knew wore only black and blue basic suits." Before, Patsy hated bananas. Now she loves them. Such changes after head injuries are mysterious but common.
Patsy is still learning about human failings. Walking through a Birmingham park, we encounter statues showing fire hoses knocking down civil rights demonstrators. Across the street is the church where a bomb killed four young girls in 1963. Patsy knows nothing about either event. "A few years ago someone asked if I thought they should hire a `colored' nurse," Patsy says. "That's when I learned about racism. I said I did not understand the problem. They then told me about colored bathrooms. I still did not understand. I said my home has three colored bathrooms, and I enjoy all three."
The accident may have biochemically destroyed Patsy's memory. The more likely explanation is that it disrupted connections to the hippocampus, which seems to play a crucial role in the long-term storage of information. Different aspects of memory reside in various parts of the brain, images in one place, for example, and emotions in another. People like Patsy help researchers map this geography. When shown a picture of a rhinoceros, one stroke victim, for example, says, "Enormous, weighs over one ton, lives in Africa." But he cannot say what it is. When asked what "rhinoceros" means, he responds "animal."
These various memory centers cannot function unless connected to the hippocampus. This means the old Patsy may still be inside but unable to assert herself.
Do pieces of old Patsy appear in dreams? "No," Patsy says, "and I don't worry about her. I'm happy with the person I am now."
No one knows what memories are. Several decades ago, scientists looked for what they called the "grandmother neuron." Then they concluded that one neuron holds grandmother's face, another her smell, and still another the sound of her voice. Now they think she is in none of these places. Memory of grandmother's face, they say, probably does not reside in a particular neuron. It exists in the changed connections between different sets of neural networks. Why do we remember some things and forget others? "Memory is not a video camera or a tape recorder," says Ulric Neisser, an Emory University psychologist. "There is no `total recall.' All memories, even very vivid ones, are more or less accurate reconstructions. Unusual experiences tend to be remembered better, because they are less confusable with other events. But even they often change to fit what we later believe must have happened."
Smell and taste are associated with many memories, because neural pathways link them directly to the hippocampus. You smell a perfume and flash back to a high school date. Novelist Marcel Proust once tasted a madeleine--a little butter cake--and was swept away by memories that resulted in the eight-volume Remembrance of Things Past.
"I fail to see why a chap needs 30 pages to describe how he tosses and turns in bed before falling asleep," one publisher's rejection letter said. But Proust's work is a literary classic. "After the people are dead, after the things are broken and scattered," he writes, "taste and smell alone, more fragile but more enduring, more unsubstantial, more persistent, more faithful, remain poised a long time, like souls, remembering, waiting, hoping, amid the ruins of all the rest."
Most of us fear losing memory. We know the name of a famous artist but can say only "the guy who went to Tahiti." Then we think, "I'm getting old."
Not necessarily. Neurons die every day, starting from the day we are born. "Even though many types of human cells--for example, the skin, liver, immune system, and stomach lining--renew themselves, the body never replaces neurons," says Pasko Rakic, a Yale University neurobiologist. "New neurons would have none of your memory. They would be another person, with a different life history. Some songbirds develop new neurons in adulthood but must relearn parts of the same songs every spring."
As brain research progresses, however, the no-new-neurons assertion cannot be made with absolute certainty. Evidence indicates that our brains may contain "progenitor cells" that could become neurons if exposed to growth-stimulating hormones. Would they perform only tasks that require new learning? No one knows.
Neural loss is continuous as we age. Older people, however, retain capacity to generate new connections and to keep old ones via mental activity. Major memory loss with age usually indicates illness or injury. My uncle's mind remained clear until his mid-70s, when he suffered small strokes during heart surgery. He began to confuse words. A "lid" instead of a "cork" sealed bottles of wine. Simple addition frustrated him, and he no longer knew the rules of chess.
The most common known cause of severe memory loss, or dementia, is Alzheimer's disease--brain lesions first identified by German neuropathologist Alois Alzheimer in 1906. It strikes between 5 and 10 percent of all people over 65 and one-quarter to one-half of those over 85.
Genetic mutation is a suspect but accounts for only 10 percent of all cases. "Early-onset" Alzheimer's, which begins around 40 or 50, runs in some families. Some Alzheimer's in older people is associated with defects in another gene that makes a protein, apolipoprotein E, that ferries cholesterol in the bloodstream and helps regenerate nerve cells. No one yet knows how it relates to neural tangles and nerve cell death.
Environment may also be significant. Studies of identical twins where one develops Alzheimer's and the other does not provide additional proof that Alzheimer's is a disease and not just the inevitable consequence of aging. Whether genetic or environmental, among primary biological suspects are tau, a protein that may play a part in forming tangles that choke neurons, and amyloid, a protein that sticks to neurons like glue. Amyloid accumulates when neurons, for unknown reasons, begin to generate more than the brain can flush out, forming plaques.
No effective treatment exists, although Allen D. Roses, a neurologist who heads the Duke University research team that discovered a gene associated with Alzheimer's, says, "In 10 or 15 years we hope to have a safe medication that a 50-year-old could take every day to prevent Alzheimer's."
If they live long enough, Alzheimer's victims forget how to chew food. Until then, the disease slowly steals the tissue that defines them. A diseased heart can be replaced with another, and life goes on, but our brains, filled with ever shifting collages of memory, define us. "It is," says one minister who works with people who have Alzheimer's, "almost as though the soul of the person changes."
I stand in the back of the room at a day-care program run by the Greater Palm Beach, Florida, chapter of the Alzheimer's Association. The room is sunny with comfortable chairs. Approximately 20 patients listen as a volunteer reads to them from the morning newspaper. Nothing outward indicates illness, except that they wear name tags and keep looking at their own.
"We try to provide mental stimulation," Mark Cornett of the Alzheimer's Association whispers. I show him a recent newspaper story. An 84-year-old man, exhausted from caring for his Alzheimer's-afflicted wife, killed her and himself. "Maybe people feel as if they're losing whatever makes them human," I say.
Mark shakes his head. "Look around," he says. "There's a lot of happiness left."
The patients do not remember their spouses or children but know the names of state capitals and other information they learned at a young age. Long-term memory is the last to go. Likewise, the brain may encode music in areas that resist Alzheimer's. Everyone joins hands and sings "I'm Looking Over a Four Leaf Clover" and "Let Me Call You Sweetheart." A man taps my shoulder. "Have you seen my letter?" he asks, holding it out.
Dear Dave,
You are in a day-care center. There are many people there who are your friends and will take good care of you.
Please cooperate with everyone, and you will have a pleasant day.
I will pick you up at 3 o'clock.
Jeannette
I am going full blast with "when the moon hits your eye" when Dave asks again, "Have you seen my letter?" The moment a conversation ends he has no memory of it.
What impresses me most is the dignity people retain. My lunch partner wears a suit and has a neatly trimmed mustache. His expressions suggest a successful business deal. He sounds earnest and sincere, but his sentences are incomprehensible. "It gets 20 to 40 percent just for them to get what they want. They will do the same things as they gave. Then nothing comes out of them." He touches the window. "If you feel this," he says, "then you get the idea. Boy, do I get it."
I comfort myself by thinking that such people forget their own deterioration. But Alzheimer's is unforgiving: It allows enough awareness to torment its victims. One man bangs his head on a table. His wife watches, love on her face. She tells me about courtship, raising children, running a business, and then, this. "We're talking about you," I say to him. "Do you know that?"
"Of course," he says, still banging.
"Your wife looks like she wants to give you a big smooch."
He smiles at her and says, "I know." Then he asks her, "What's happening to me?"
I have been seeing quiet miracles: the brain itself, growing medical mastery of it, and, perhaps the greatest, the power of courage and of love. All form the foundation for the new era we are entering.
New clinical treatments will emerge amid dissolving distinctions between "physical" and "mental." Mapmakers will redefine inner geography, forcing us to reexamine how we perceive ourselves and raise our children. At the same time, our brain maps will constantly change as new discoveries challenge old truths.
The brain's marvelous adaptability, especially during childhood, is firmly established. This adaptability, coupled with the brain's immeasurable potential, encourages faith in dreams--no matter what our age or life circumstance.
Valerie Simpson calls with an update on Matt. He is doing well in third grade--lots of B's and some A's. He gets along well with other children and is happy.
Matt can use his right arm better. He still limps, but less. Brain scans show that control over his right arm and leg has settled into the cortical area that controls his left arm and leg--the brain seems to have a strong sense of consistency. He is enjoying school, but there are those who insist that he will never do as well as his contemporaries. They make Valerie angry. "Who's to define the sky for Matthew?" she asks.
Who's to define the sky for any of us?
Copyright 1995 National Geographic Society. All rights reserved.
